Hello Joe, Im not at all an expert in this area actually quite the opposite. Ive just started out trying to understand wireless communication and its quite complex. I am how ever trying to do almost the same project like youre doing and I have a different approach.In your case it would be something like this:Arduino on the RC car has a Xbee module connected to it either via a xbee shield or a breakout board. That xbee recieves the wireless information and converts it into easy handle serial communication for the arduino. At the computer you have an Xbee explorer Usb (just search sparkfun and you'll find em) with another xbee module plugged into. With the computer you can then send serial communication commands to the xbee which will be wirelessly transfered to the other xbee which will convert it back to seral communication.

At the computer you could use the Programming interface called Processing, Im not aware of any other alternative but im sure there are plenty!I hope that helped you!good luck on your project!

http://www.ebay.com/itm/315Mhz-WL-RF-transmitter-and-receiver-link-kit-for-Arduino-ARM-MCU-/370776247168?pt=LH_DefaultDomain_0&hash=item5653fc8b80Ebay Just $1.50 a pair!

Unfortunately, I don't have two Arduino's so I've chosen a harder road: Communicating between an Attiny85 and an Arduino UNO. I created a similar topic for this so if you interested go look at it as well.

http://arduino.cc/forum/index.php/topic,154684.0.html

But yeah, if you have two Arduinos communicating, I guess it would be cheaper and much simpler. XBee's are good options but they are hard to configure (according to other peoples views, not mine) and pretty darn expensive!. But personally I think RX communications is much simpler. Plus the RX antena's have a amazing range if you add a simple additional antenna to them (consisting from just a wire that picks up signals).